boost/function_types/detail/class_transform.hpp
// (C) Copyright Tobias Schwinger // // Use modification and distribution are subject to the boost Software License, // Version 1.0. (See http://www.boost.org/LICENSE_1_0.txt). //------------------------------------------------------------------------------ #ifndef BOOST_FT_DETAIL_CLASS_TRANSFORM_HPP_INCLUDED #define BOOST_FT_DETAIL_CLASS_TRANSFORM_HPP_INCLUDED #include <boost/mpl/apply.hpp> #include <boost/mpl/always.hpp> #include <boost/mpl/identity.hpp> #include <boost/mpl/placeholders.hpp> #include <boost/type_traits/remove_cv.hpp> #include <boost/type_traits/add_pointer.hpp> #include <boost/type_traits/add_reference.hpp> namespace boost { namespace function_types { namespace detail { using mpl::placeholders::_; // Transformation metafunction for the class type of member function pointers. template<typename T, typename L> struct class_transform { typedef typename mpl::apply1<L,T>::type type; }; // We can short-circuit the mechanism implemented in the primary template for // the most common lambda expression and save both the "un-lambdaing" and the // type traits invocation (we know that T can only be a class type). template<typename T> struct class_transform< T, mpl::identity<_> > { typedef T type; }; template<typename T> struct class_transform< T, add_reference<_> > { typedef T & type; }; template<typename T> struct class_transform< T, add_pointer<_> > { typedef T * type; }; template<typename T> struct class_transform< T, remove_cv<_> > { typedef typename boost::remove_cv<T>::type type; }; template<typename T> struct class_transform< T, add_reference< remove_cv<_> > > { typedef typename boost::remove_cv<T>::type & type; }; template<typename T> struct class_transform< T, add_pointer< remove_cv<_> > > { typedef typename boost::remove_cv<T>::type * type; }; template<typename T, typename U> struct class_transform< T, mpl::always<U> > { typedef U type; }; } } } // namespace ::boost::function_types::detail #endif